1) The oil level is too low
2) The cooler is blocked
3) There is hot gas reflux in the expansion air trough
4) Insufficient cooling air volume
5) The thermostatic valve is stuck
6) Poor flow of cooling water (negative pressure)
7) The inlet temperature of cooling water is too high
8) The oil break valve is stuck
9) The return pipe is blocked
10) The pressure difference of oil and gas separator is too large
11) The rear cooler is blocked
12) Oil filter is blocked
13) Air filter is blocked
14) Problems exist in the rotor
15) Oil cooler blocked
16) The piston of unloading valve is damaged and stuck
17) Minimum pressure valve stuck
18) Hose leakage and blockage